Modern mechanical EM transmitters, like radio towers and radar guns, rely on finely tuned mechanical structures. If these structures do not have the right shapes, the device fails to function.
Organic growth focuses on balances and on-the-fly tuning. It has to grow from infant to adult sizes. Organics tend to adapt to incorrect shapes, rather than rebuiling them to be the right shape.
Consider two uses for EM:
- Radar style sensing (which requires tremendous dynamic range)
- Communication (which requires fine tuning and allocation of bandwidth)
If we were to evolve such capabilities in one of the creatures we dream up, what would have to be fundamentally different than today's mechanical devices.
Particular features of today's devices that I think would cause a challenge:
- Precise clocks. For things like wifi to work, a clock needs to have under 20ppm of error (I think that number is a jitter number, but it might have been a bias number). The demands of radar are often even higher. The jitter requirements on modern pulse-doppler radars are brutal!
- Highly linear RF-frequency amplifies, needed to modulate or demodulate a signal.
- Demanding antenna geometry (which may need to be identical across multiple individuals)
- Dynamic range (we have radars today that output megawatts, and listen to echos in the femtowatt range!)
- Privacy (hard unless you rely entirely on digital communications)
- Lack of subtlety (our radios have no concept a. la tone of voice or body language)
Edit: I am particularly interested in the use of lower frequencies, such as microwaves and radio waves, where the wave mechanics force a macroscopic antenna.